CVE-2022-48857 is a use-after-free (UAF) vulnerability identified in the Linux kernel's NFC subsystem, specifically within the port100 driver. The vulnerability arises due to improper error handling in the probe function of the port100 NFC driver, where USB Request Blocks (URBs) are not properly killed on error paths. The port100_send_complete() function accesses memory allocated via devm_kmalloc(), which is freed if the probe function fails. However, because usb_kill_urb() calls are missing on the error handling path, the URBs may still attempt to access this freed memory, leading to a use-after-free condition. This was detected and reported by Syzbot, a kernel fuzzing infrastructure, and confirmed by Kernel Address Sanitizer (KASAN) logs showing invalid memory reads during the port100_send_complete() execution. The root cause is a missing usb_kill_urb() invocation before returning an error from the probe function, which would otherwise prevent the use-after-free by ensuring that URBs are properly canceled. The vulnerability affects the Linux kernel NFC port100 driver, which handles Near Field Communication devices connected via USB. Exploitation of this flaw could lead to kernel memory corruption, potentially causing system crashes (denial of service) or enabling escalation of privileges if exploited by a local attacker. The vulnerability requires interaction with the NFC device and the presence of the port100 driver. There is no CVSS score assigned yet, and no known exploits in the wild have been reported. The issue was fixed by adding the missing usb_kill_urb() calls to the error handling path in the probe function, ensuring safe cleanup of allocated resources. This vulnerability is technical and specific to Linux kernel versions containing the vulnerable port100 driver code prior to the fix.

For European organizations, the impact of CVE-2022-48857 depends largely on the deployment of Linux systems utilizing the port100 NFC driver. Organizations using Linux servers, desktops, or embedded devices with NFC hardware supported by port100 are at risk. Potential impacts include system instability or crashes due to kernel memory corruption, which can disrupt critical services and operations. More severe exploitation could allow local attackers to escalate privileges, compromising system confidentiality and integrity. This is particularly concerning for sectors relying on NFC for secure access control, payment systems, or identity verification, such as finance, transportation, and government agencies. Given the Linux kernel's widespread use in European infrastructure, including cloud services, telecommunications, and industrial control systems, unpatched systems could face increased risk of targeted attacks or accidental disruptions. However, exploitation requires local access or interaction with the NFC device, limiting remote attack vectors. The absence of known exploits reduces immediate threat but does not eliminate risk, especially as attackers may develop exploits post-disclosure. Organizations with strict security requirements and those using NFC-enabled Linux devices should prioritize patching to prevent potential privilege escalation or denial of service.

1. Apply official Linux kernel updates that include the patch fixing CVE-2022-48857 as soon as they become available. Monitor vendor advisories for updated kernel packages. 2. For systems where immediate patching is not possible, consider disabling the port100 NFC driver if NFC functionality is not required, reducing the attack surface. 3. Implement strict access controls to limit local user access on Linux systems, minimizing the risk of local exploitation. 4. Monitor system logs for unusual kernel errors or crashes related to NFC or USB subsystems, which may indicate exploitation attempts. 5. Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and Kernel Page Table Isolation (KPTI) to reduce exploitation success. 6. For embedded or specialized devices using NFC, coordinate with hardware vendors to ensure firmware and driver updates are applied. 7. Conduct security audits focusing on NFC device usage and Linux kernel versions in use to identify vulnerable systems. 8. Educate system administrators about the risks associated with NFC drivers and the importance of timely patching.